The present invention relates to a computer-controlled apparatus and method for depositing foods/sauces into plastic trays that are moving at high speed using servomotors coupled to a computer. A pump with a three column output is driven by a first servomotor to provide a food deposit which is fed through three tubes to a cut-off nozzle housing. A second servomotor drives a rocking cut-off valve within the stationary cut-off housing to deposit a predetermined measure in a moving tray.
To fill trays with food or sauces, a typical apparatus of the prior art generally requires three reciprocating cylinders to pump the food product to respective outlets and a carousel to move the three filling outlets over the trays at the same speed as the trays in order to fill the trays without leaking or spilling over the edges.
The prior art apparatus is large in size, requires complicated pneumatic control systems and complicated mechanical parts in order to operate. There is considerable maintenance involved with this equipment (down time), there are many parts to clean at the end of each production run and making weight deposit adjustments requires tools to set mechanical stops. Accuracy across all three cylinders tends to vary due to unique wear on each of the cylinders. This means that there is always the possibility of weight variation in each tray. Because the three cylinders are driven from one common source, adjusting weights is complicated. All of these issues combined add up to long setup times, usually requiring qualified maintenance personnel.
In the prior art, U.S. Pat. No. 5,906,297 to Cole discloses a multi outlet depositor that displaces first and second portions of material and includes first and second positive displacement vane pumps. The pumps are coupled together so that the volume of the first portion varies according to the volume of the second portion.
The state of the prior art is also shown in patents such as U.S. Pat. No. 6,212,861 to Tsuruta on a Forming, Filling and Sealing Machine for Standing Pouch and U.S. Pat. No. 6,058,680 to Meile, et al on a Method and Apparatus for Forming and Hermetically Sealing Slices of Food Items. Also of interest are U.S. Pat. Nos. 5,155,969 to Kue and 4,997,664 to Williams. The prior art fails to disclose an apparatus of the type disclosed herein which uses a single positive displacement gear pump driven by a servomotor, controlled by a computer via a user-friendly touch screen to feed food product to a plurality of tubes over the trays. The apparatus includes a rocking plastic cut-off nozzle that is driven by a second servomotor. The nozzle is coupled to a stationary housing.
Applicant's application, Ser. No. 10/064,308, filed Jul. 1, 2002 now U.S. Pat. No. 6,715,519 discloses a positive displacement gear pump driven by a first servomotor and a cut-off nozzle driven by a second servomotor. The pump feeds product to a horizontal tube which cooperates with a rotating cut-off nozzle to deliver product to a series of fast moving trays. While the design works well with certain fillings, applicant is concerned with fillings that are smooth and uniform and fillings that have chunks blended with water juices.